Agitator wheel



April 1962 H. A. STIFFLER 3,030,083

AGITATOR WHEEL Filed March 25, 1959 2 Sheets-Sheet 1 IF Iii-2 \Y, MINVENTUFJ HUEHASTIFFLEW 49 z? 4? ATTUEINEY 40%fiffluazza P 1962 H. A.STIFFLER 3,030,083

AGITATOR WHEEL Filed March 25, 1959 2 Sheets-Sheet 2 senses PatentedApr. 17, 1962 fifice Filed Mar. 25, 1959, Ser. No. 801,943

' 2 Claims. (Cl. 259-134) This invention relates to a device foragitating and m1xing fluids ranging in viscosity from that approachingwater up to and including thick viscous material such as paints andtars. The device embodying the invention comprises essentially one ormore wheels to be rotated in the fluids as opposed to beingreciprocated,and the efiicacy of the wheel depends upon its creating a considerableturbulence inducing eddy currents wherein the individual particles ofthe materials being agitated or mixed will cross and recross each otherrepeatedly over a rather wide range of wheel rotating speeds;

The individual wheel comprises primarily a plate rotatable in a plane ofdirection of rotation, with leading and trailing edges extending fromdiscrete blades radially extending from the plate, at forty-five degreeangles to the plate, and having holes of specific arrangement and sizesthrough the individual blades for the setting up of eddy currents andcavitation pockets further inducing eddy currents all to the end thatthe fluid will be turbulent within local zones rather than anydependence being placed upon moving the liquid as a body incircumferential travel within a container.

In addition to the above indicated purposes of the invention ofproducing the high degree of turbulent eddy motion of the fluid beingworked upon, there is the advantage of the relative low cost ofproduction of the device embodying the wheel, and also the requirementof a relatively low power input to turn the wheel. As to the fluidsbeing mixed, itis within the scope of the invention to employ the wheelor wheels in forming solutions of various elements'or compounds insolutes as may be required.

This application is a continuation in part of applicants applicationSerial No. 721,486, filed March 18, 1958, and now abandoned.

With the foregoing objects and advantages of the invention in mind,reference is made to the accompanying drawings, in whicha FIG. 1 is aview in side elevation of a structure embodying the invention involvingtwo wheels;

FIG. 2 is a view in top plan of a blanked wheel before forming;

'FIG. 3 is a view in FIG. 1; 1

FIG. 4 is a view in top plan of the lower wheel in FIG. 1; and 7 FIG, isa view in perspective of a fragmentary portion of a blade of the lowerwheel.

Referring first to the blank form of the wheel as illustop plan of theupper wheel in trated in FIG. 2, the description will be confined to oneparticular sizeof wheel, namely a six and one-half inch wheel. The wheelmay be made in innumerable sizes, depending upon the job to beperformed, and primarily the size ofthe container of the fluid withinwhich the wheel is to be employed.-

For this one particular size of wheel, the blank generally designated bythe numeral 10 is primarily, circularly formed to have theoutercircumferential edge 11. Slits 12, five-sixteenths of one inchwide, are provided to extend radially inward from the outercircumferential line 11 at regular intervals around the blank 10, hereinshown as The slit 12 in each instance opens by its inner radial end intoa generally elliptical'openin g 14having an inner:

arcuate edge 15 defined by the circumference of a circle of one andone-quarter inch radius from the center'E of the blank, this curvatureof the edge 15 merging into the substantially semicircular ends 16 and16a of onequarter inch radius from which theredge of the openingcontinues through a radius 17 in each instance merging into the sides ofthe slits 12. The outer ends of the edges of the slit 12 merge througharcuate portions 18 into the circumferential edge 11. The centralportion of the blank 10 is provided with an opening 19 to receive a hub20, FIG. 1, the opening through the hub 26 being of that diameter whichwill receive a driving shaft 21.

Each of these blades 13 has a major truncated, approximately triangularplanar area disposed in a plane common to all of said blade areas andextending from the central portion of the blank 10 and lying between thelines AB and CD (below located), FIG. 5, and the outer periphery 11.This plane of the blades 13 is at a right angle to the axis of rotationof the wheel with the shaft 21. The major width or base portion of eachblade 13 lies Withinthe outer peripheral margin of the blade.

Each blade 13 is provided with a generally central hole 22 therethrough,the center of which in. each instance is located on a circle having aradius of two and sevensixteenths inches from the center E. Each blade13 will have a leading edge portion 23 and a trailing edge portion 24.These portions 23 and 24 will be bent from the planar plate, preferablyat forty-five degrees thereto, the portion 23 being bent downwardly onthe dash line 23a and the portion 24 being bent upwardly on the dashline 24a; These dash lines 23a and 24a will curve at their inner ends toterminate in the edge 15.

As indicated in FIG. 2, the bend line 23a if extended will be identifiedas a line C-D being tangentialto the one inch circle of the opening 19at C, and being disposed at an angle of seven degrees from the centerline E-F of the slit 12. Likewise the line 24a will be identified as theline A--B if extended, and it will be tangential to the circle of theopening 19 at A, and it will slope from the line E-F by seven degreesalso. The side portions .23 and 24 so formed with the wheel-non-radialbend lines aresubstantially parallelograms.

A plurality of holes which may be termed inner holes 25, eachthree-eighths of one inch in diameter, are centered on the circumferenceof a circle having a radius of two and one-sixteenths inches from thecenter E, and these holes 25, in relation to the blank shown in FIG. 2,

. are centered eleven-sixteenths of one inch to each side of the lineE-F. This positions the holes 25. in each instance to havethe side mostremoved from the line E--F substantially on the bend lines 231; and 24a.In fact, there is a slight overlapping of these holes across the bendlines as indicated in FIG. 2. Thus, there are two of these holes 25 foreach blade 13, being located adjacent the openings 14. a

In each of the edge portions 24,there is a second hole 26 three-eighthsof one inch in diameter, centered on a circle of two andthirteen-sixteenths inches radius from the center E, and located in eachinstance eleven-sixteenths of one inch from the line E- F.

'In the edge portion23, toward the outer circumferential edge 11, thereis positioned in each blade an elliptical hole 27 having ends ofthree-sixteenths inch radius spaced apart from centers three-sixteenthsof one inch. This hole merges with the edge 15. This curvature isconfined within the radial length cross the opening 14.

The blank thus formed may for the sake of convenience carry the samenumeral 10 to identify it as the lower wheel as shown in FIG. 1. Theupper wheel 30 which will be carried by the shaft 21 is identical withthe wheel 10 with the important exception that the blade edge sideportions are reversed in their directions of bending from the plate.That is to say, assuming that the shaft 21 is rotating in the directionof the arrow, the upturned edge portion 31 of each blade 13 becomes theleading edge whereas the downturned edge portion 32 beca-mes thetrailing edge.

As indicated in FIG. 1, the wheel 30 will be spaced a distance above thewheel 10, this distance depending of course upon the depth of the vesselcontaining the fluid to be agitated, and the speed of rotation of theshaft 21. Additional wheels may be positioned along the shaft 21 fordeeper vessels. The speed of rotation of the shaft 21 may range from arelatively low speed such as five hundred revolutions per minute or evenless and on up to higher speeds again depending upon the nature of thematerial to be handled. For example, the six and onehalf inch diameterwheel as has been above described will operate satisfactorily betweenspeeds of five hundred to one thousand r.p.m. It is to be'understoodthat the wheels may be employed in mixing plasters, cement,sand andwater mixtures and the like. In any event, it is intended that all thewheels which may be on the shaft 21 will remain submerged duringoperation, and that the lower wheel such as the wheel 10 will be nearthe bottom of the container. Where materials such as paint, are to bemixed, the speeds may go up to fifteen hundred r.p.m.

There will be no vortex appearing in the fluid, and hence there will beno air introduced during the mixing or dissolving process as the wheelsturn. Furthermore, there will be no flow out nor splashing of thematerial. The speeds above indicated apply to the more viscousmaterials, but when the viscosity is greatly reduced, speeds may go upto three thousand r.p.m. Colloidal solutions as well as emulsions arereadily produced with a minimum amount of foaming. As previouslyindicated, there will be different diameter sizes of wheels forparticular jobs.

The source of power has not been shown nor described since the shaft 21may be turned by ordinary drill motors, air motors, and the like inwhich case the shaft 21 would be engaged by the chucks of such motors.Obviously other power sources may be employed.

Operation The wheels 10 and 30 combine translatory andturbulent eddymotion over the range of the wheel rotating speeds. The use of the holesor orifices in the plate and in the turned planar surfaces particularlyaid in this motion of the material being agitated. As the wheel ineither case, or in both cases, wheels 10 and 30, are rotated, cavitationbehind the up and downturned marginal edges of the blades would occurwere it not for the orifices presented, and the particular sizing andlocations of these orifices set up the eddy currents induced by thevelocity and flow of the material therethrough or thereover, setting upa difference between the intensity of the pressure on one side of thewheel in comparison to the other side with the opening through theorifices therebetween, and contrary to good orifice design, the locationand sizes of these orifices have been designed to set up the maximumeddy currents rather than the minimum. It is to be considered that theseorifices are at all times submerged so that the ordinary concepts inhydraulics are not to be employed since it is the intended purpose ofthe design of these wheels to go to the contrary of good design formaximum unidirection of flow in the ordinary propeller wheel.

What goes on during the rotation of a wheel may be visualized somewhatin referring to FIG. 5, and assuming that the blade 13 is moving in thedirection of the main arrow thereabove.

Defining the blade 13 more in detail, between the lines AB and C-D, FIG.5, there is the triangular portion 33, truncated in effect, with thebase of the triangle in the circumferential line 11. The edge portions23 and 24 are essentially parallelograms planar each in its fortyfivedegrees angle slope, whereas the triangular portion 33 is planar, in aplane lying in the direction of rotation of the wheeL Arrows have beenapplied in FIG. 5 to indicate relative motion of the fluid in relationto the individual blade 13 as it travels through the fluid. The fluidwill be generally lifted in the direction of the arrow 34, sliding upthe inclined portion 23, and tending to continue upwardly somewhat abovethe plane of the section 33, leaving a slight pressure built up underthat upwardly directed current, causing some of the fluid to reverse inthe direction of the arrow 35 and curl around through the hole 22 to theunder side of the section 33. Some of the reverse current will followthe direction of the arrow 36' around and over the plate section 33tending to exit through the hole 26 to the back side of the trailingedge portion 24. The major portion of the fluid will take the directionof the arrow 37 while that going through the hole 26 will be indicatedby the arrow 38.

Some of the fluid being pressed against by the leading downturned edgeportion 23 will follow the directions of the arrows 39 and 40 throughthe holes 25 and 27 respectively again going to the under side of theplate section 33. Some of the fluid upon striking the trailing upturnededge portion 24 will continue on upwardly and tend to curl over andforwardly in the direction of the arrow 41, while some will completelycurl over in the direction of the arrow 42 and escape through the hole22. Other portions of the fluid will tend to escape through the hole 25in the section 24 as in the direction of the arrow 43.

Under the blade 13, there will tend to be some cavitation particularlyunder the line CD, but this is promptly filled in by fluid comingthrough the holes 25 and 27, as well as by the fluid entering throughthe hole 22 under a slightly increasing pressure, and thefluidthereunder will tend to curl around in the direction of the arrow44. The fluid under the major area of the triangular section 33 will bein a state of turmoil, turbulent and eddying about, further augmented byreason of the fact that there will be a downflow behind the trailinginclined portion 24 somewhat in the'direction of the arrow 45. Thenagain, there will be some slippage of the fluid radially of the blade 13further augmenting the crossing and recrossing of the particles of fluidand mixture being agitated. In other words, the Wheel 10 of which thisblade 13 is a part as shown in FIG. 5 is not a propeller in the truesense, but is strictly an agitating device intending to lift and dropand recirculate the fluid locally over the individual blade 13, in partthrough it, so that there is no major single current of fluid set up.

The upper wheel 30 does the same thing as has been described in relationto the wheel 10 and its blade 13 of FIG. 5, but doing so in reversesince that wheel is a reverse counterpart of the wheel 10, and thereforethe agitation between the wheels is considerable with this turbulenceproduced by the eddying therebetween as well as above.

Therefore it is to be seen that I have produced an exceedingly simpleand yet most effective wheel design for the purpose as indicated, andthe various elements including the orifices have been arranged toaugment the turbulent effect in the fluid. Therefore While I havedescribed the individual wheel in minute detail, it is obvious thatstructural changes might be made without departing from the spirit ofthe invention, and I therefore do not desite to be limited to thatprecise form beyond the limitations which may be imposed by thefollowing claims.

I claim:

1. For mixing, blending, and emulsifying fluid compositions, a rotaryWheel comprising a central driving portion; a plurality of individualblades extending from said portion, each blade having a major truncated,approximately triangular planar area in a plane common to all of saidblade areas, said plane being at a right angle to the axis of rotationof said wheel, and said area having its major width lying in the outerperipheral margin of the blade; a blade side portion sloping atapproximately forty-five degreesfrom along one side of the planar areaof each blade; and a second blade side portion sloping at approximatelyforty-five degrees from the other side of the blade planar area and inan opposite direction from the first side portion; the junctures of saidside portions with said planar areas being on lines non-radial of saidwheel; each of said blade planar areas having a major size hole locatedapproximately centrally of the area,

and a pair of lesser sized, spaced apart holes in each of said sideportions located at said junctures, the hole in one of said pairs mostremote from said wheel center portion being generally elliptical andextending in part by an end portion across said juncture to enterthrough said planar area.

2. The structure of claim 1 in which the major axis of said ellipticalhole extends substantially circumferentially of the Wheel; the other ofsaid lesser sized holes are approximately tangential to said juncturelines; and said blade side portions being substantially planarparallelograms.

References Cited in the file of this patent UNITED STATES PATENTS1,296,663 Holden Mar. 11, 1919 2,530,858 Cerniak Nov. 21, 1950 2,673,077Messbauer Mar. 23, 1954 2,736,537 Nelsson Feb. 28, 1956

